Strange particles and neutron stars -

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Strange particles and neutron stars - experiments
at GSI
Peter Senger (GSI)
Outline Probing dense baryonic matter (1-3 ?0)
?The nuclear equation-of-state ? In
medium properties of strange mesons Towards
highest baryon densities (3-10 ?0) ?
Exploring the phases of QCD matter
International Symposium on Heavy-Ion Physics,
April 2-6, 2006, Frankfurt
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Strongly interacting matter in neutron stars
color superconductor ?
Strangeness" of dense matter ? In-medium
properties of hadrons ? Nuclear matter equation
of state ? Deconfinement at high baryon densities
?
nucleon star kaon condensate
F. Weber J.Phys. G27 (2001) 465
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Kaon production in AuAu collisions at 1 AGeV
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Probing the nuclear equation-of-state at high
density by K meson production in CC and AuAu
collisions
C. Sturm et al., Phys. Rev. Lett. 86 (2001) 39
Idea K yield ? baryon density ?
? compressibility ? AuAu at 1 AGeV (RBUU)
soft eos ? ?max? 2.9 ?0 ? K yield up hard eos
? ?max? 2.4 ?0 ? K yield down but in CC no
influence of eos on K yield !
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QMD transport calculations
C. Fuchs et al., Phys.Rev.Lett. 86 (2001) 1974
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The compressibility of nuclear matter
Experiment C. Sturm et al., Phys. Rev. Lett. 86
(2001) 39
Theory QMD C. Fuchs et al., Phys. Rev. Lett. 86
(2001) 1974 IQMD Ch. Hartnack, J.
Aichelin, J. Phys. G 28 (2002) 1649
Figure by C. Fuchs
soft equation-of-state k 200 MeV
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K mesons in dense matter
G.E Brown, C.H. Lee, M. Rho, V. Thorsson, Nucl.
Phys. A 567 (1994) 937 T. Waas, N. Kaiser, W.
Weise, Phys. Lett. B 379 (1996) 34 J.
Schaffner-Bielich, J. Bondorf, I. Mishustin
, Nucl. Phys. A 625 (1997)
In-medium spectral functions of K-, ? (1405) and
? (1385)
M. Lutz, C. Korpa, Nucl. Phys. A 700 (2002) 309
self-consistent coupled channel calculation
(s,p,d waves)
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In-medium modifications of K mesons
Data M. Menzel et al., KaoS Collab., Phys.
Lett. B 495 (2000) 26 K. Wisniewski et
al., FOPI Collab., Eur. Phys. J A 9 (2000) 515

Figure by C. Fuchs
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K azimuthal emission pattern from AA collisions
Data Y. Shin et al., Phys. Rev. Lett. 81
(1998) 1576 F. Uhlig et al.,
Phys.Rev.Lett. 95 (2005) 012301 Theory A.
Larionov, U. Mosel, nucl-th/0504023
Evidence for repulsive KN interaction !
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NiNi at 1.93 AGeV p, K and K- azimuthal
distributions
F. Uhlig et al., Phys. Rev. Lett. 95 (2005)
012301
3.8 fm lt b lt 6.4 fm 0.4 lt y/ybeam lt0.6 0.2
GeV lt p-lt 0.8 GeV
IQMD CalculationC. Hartnack et al.
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AuAu 1.5 AGeV semi-central collisions (b gt 6.4
fm) K and K- azimuthal angular distributions
M. Ploskon, PhD Thesis 2005
dN(f)/f ? 1 2v1cos(f) 2v2cos(2f) ...
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Elliptic flow of K and K- mesons Comparison to
off-shell transport calculations and in-medium
spectral functions
Data M. Ploskon, PhD Thesis, Univ. Frankfurt
2005 Off-shell transport calculations W. Cassing
et al., NPA 727 (2003) 59, E. Bratkovskaya,
priv. com. Coupled channel G-Matrix approach (K-
spectral functions) L. Tolos et al., NPA 690
(2001) 547
dN(f)/f ? 1 2v1cos(f) 2v2cos(2f) ...
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The Kaon Spectrometer at SIS (1991 2002)
Collaboration
GSI Darmstadt P. Koczon, F. Laue, M. Ploskon,
E. Schwab, P Senger, C. Sturm TU Darmstadt
A. Förster, S. Lang, H. Oeschler, A. Schmah, F.
Uhlig Univ. Frankfurt Y. Shin, T. Schuck, H.
Ströbele Univ. Marburg I. Böttcher, B.
Kohlmeyer, M. Menzel Univ. Kraków M.
Debowski, G. Surówka, W. Walus FZ Rossendorf
F. Dohrmann, E. Grosse, L. Naumann, W.
Scheinast, W. Wagner
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Towards higher baryonic densities
Ch. Fuchs, Tübingen
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Transport calculations baryon and energy
densities
Baryon density in central cell (AuAu, b0
fm) QGSM Cascade, hadrons resonances strings
C. Fuchs, V. Toneev

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Trajectories from UrQMD
H. Stöcker nucl-th/0506013
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Trajectories from 3 fluid hydrodynamics
Hadron gas EOS Y. Ivanov, V. Russkikh, V.Toneev
nucl-th/0503088
early phase (first 2 fm/c) not in thermodynamic
equilibrium !
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Intriguing observations by NA49 _at_ CERN-SPS
PbPb
?
next steps ?confirmation of NA49 ? Low energy
run at RHIC ? ?comprehensive experimental study ?
CBM _at_ FAIR
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Diagnostic probes of compressed baryonic
matter UU 23 AGeV
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Compressed Baryonic Matter physics topics and
observables
Probing the equation-of-state at high ?B
Observables collective flow of hadrons,
particle production at threshold energies
(open charm)
Search for a deconfined phase at high ?B
? enhanced strangeness production ?
Observables K, ?, ?, ?, ? ? anomalous
charmonium suppression ? Observables
charmonium (J/?, ?'), open charm (D0, D?)
Search for chiral symmetry restoration at high
?B ? in-medium modifications of hadrons
Observables ?, ?, ? ? ee- , open
charm, .....
Search for the 1. order phase transition the
critical endpoint Observable
event-by-event fluctuations (K/p, pT, ...)
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Experimental program of CBM
Observables Penetrating probes ?, ?, ?, J/? ?
ee- (µµ-) Strangeness K, ?, ?, ?, ?, Open
charm Do, D?, Ds, ?c, global features
collective flow, fluctuations, ..., exotica
Systematic investigations AA collisions from 8
to 45 (35) AGeV, Z/A0.5 (0.4) pA collisions
from 8 to 90 GeV pp collisions from 8 to 90
GeV Beam energies up to 8 AGeV HADES
Detector requirements Large geometrical
acceptance (azimuthal symmetry !) good hadron
and electron identification excellent vertex
resolution high rate capability of detectors, FEE
and DAQ
Large integrated luminosity High beam intensity
and duty cycle, Available for several month per
year
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Meson production in central AuAu collisions
W. Cassing, E. Bratkovskaya, A. Sibirtsev, Nucl.
Phys. A 691 (2001) 745
SIS100/ 300
SIS18
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The CBM Experiment
Silicon Tracking System (STS)
? Radiation hard Silicon (pixel/strip) Tracking
System in a magnetic dipole field ? Electron
detectors RICH TRD ECAL pion suppression
better 104 ? Hadron identification TOF-RPC ?
Measurement of photons, p, ?, and muons
electromagn. calorimeter (ECAL) ? High speed data
acquisition and trigger system
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Experimental challenges
Central AuAu collision at 25 AGeV URQMD
GEANT4 160 p, 400 ?-, 400 ?, 44 K, 13
K-,....

• ? 107 AuAu reactions/sec
• (beam intensities up to 109 ions/sec,
• 1 interaction target)
• ? determination of (displaced) vertices
• with high resolution (? 50 ?m)
• ? identification of electrons and hadrons

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CBM 8 45 AGeV
and outlook
HADES 2 8 AGeV
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CBM Collaboration 40 institutions, gt 350
Members
Croatia RBI, Zagreb China Wuhan Univ. Hefei
Univ. Cyprus Nikosia Univ.   Czech
Republic CAS, Rez Techn. Univ. Prague France
IReS Strasbourg Hungaria KFKI Budapest Eötvös
Univ. Budapest India VECC Kolkata    
Romania NIPNE Bucharest Russia IHEP
Protvino INR Troitzk ITEP Moscow KRI, St.
Petersburg Kurchatov Inst., Moscow LHE, JINR
Dubna LPP, JINR Dubna LIT, JINR Dubna MEPHI
Moscow Obninsk State Univ. PNPI Gatchina SINP,
Moscow State Univ. St. Petersburg Polytec.
U. Ukraine Shevshenko Univ. , Kiev
Korea Korea Univ. Seoul Pusan National
Univ. Norway Univ. Bergen Germany Univ.
Heidelberg, Phys. Inst. Univ. HD, Kirchhoff Inst.
Univ. Frankfurt Univ. Kaiserslautern Univ.
Mannheim Univ. Münster FZ Rossendorf GSI
Darmstadt Poland Krakow Univ. Warsaw
Univ. Silesia Univ. Katowice   Portugal LIP
Coimbra
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Summary
and outlook
Probing dense baryonic matter (1-3 ?0)
Excitation function of K production in AA
collisions ? The nuclear matter
equation-of-state is soft ( K ? 200 MeV)
Yield and elliptic flow of K mesons ?
The in-medium potential of K mesons is
repulsive Yield and elliptic flow of K-
mesons ? Quantitative interpretation of
data requires off-shell transport
calculations and in-medium spectral functions
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Theoretical prediction of meson production in
central AuAu collisions
Hadron String Dynamics transport calculation W.
Cassing, E. Bratkovskaya, A. Sibirtsev, Nucl.
Phys. A 691 (2001) 745
SIS100/ 300
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D mesons from AuAu collisions at 25 AGeV
Track reconstruction realistic magnetic field,
7 pixel detectors (no strips yet), no particle
ID required
D production cross section from HSD 25 AGeV
AuAu from UrQMD
81000 D mesons registered in 1012 min. bias
AuAu collisions at 25 AGeV ? 1 day run with fast
and rad hard vertex detector and tracking trigger
? 100 days run with todays MAPS vertex detector
without trigger
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In-medium modification of D-mesons
E. Bratkovskaya, W. Cassing
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Extreme states of strongly interacting matter
baryons hadrons partons

Compression heating quark-gluon
matter (pion production)
Neutron stars
Early universe
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Off-shell transport calculations
L. Tolos et al., NPA 690 (2001) 547 coupled
channel G-Matrix approach K- spectral functions
off-shell HSD W. Cassing et al., NPA 727 (2003)
59
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Mapping the QCD phase diagram with heavy-ion
collisions
LHC
RHIC
crossover transition
lattice QCD
SPS

Critical endpoint Z. Fodor, S. Katz,
hep-lat/0402006 S. Ejiri et al.,
hep-lat/0312006 µB lt ?400 MeV crossover
SIS300
SIS18
baryon density ?B ? 4 ( mT/2?)3/2 x
exp((?B-m)/T) - exp((-?B-m)/T) baryons
- antibaryons